Treatment device

ABSTRACT

A treatment device is provided including a catheter having a lumen that is opened to a distal end of the catheter; a wire passing through the lumen so that the wire is inserted into or retracted from the lumen; and a piece disposed at a distal end of the wire and having the maximum width when the piece is protruded from the distal end of the catheter is set larger than the diameter of the lumen, wherein the piece body is formed of a deformable material having a broad curved surface shape that distributes concentration of pressure acting on tissues, and when the wire is pulled in toward the catheter, the piece being extended in the axial direction by the lumen and reduced in its outer diameter so as to be pulled into the lumen.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a treatment device that is insertedthrough a natural orifice of a human into a duct cavity.

2. Description of Related Art

Endoscopic retrograde cholangiopancreatography (ERCP) has been known asa method of diagnosing abnormalities of the pancreas, gallbladder, orbile ducts. In ERCP, a catheter is inserted through the papilla of theduodenum, and then a contrast agent is injected directly through thepancreatic or bile ducts, thereby allowing X-ray images to be acquired.

If the entrance of the papilla is narrow or the lining of the bile ductis curved, it is difficult to insert the catheter into the bile duct.Excessive stabbing of the entrance of the papilla with the catheter maycause a mucous membrane edema, unnecessarily narrowing the entrance.Moreover, when the catheter is thrust into a submucosa through themucous membrane when stabbing the entrance with the catheter, insertionof the catheter becomes more difficult. When a contrast agent isinjected in a state that the catheter is thrust into the submucosa, thecontrast agent will be injected into the submucosa so that the mucousmembrane is inflated to further obstruct the entrance of the papilla.Moreover, when the edema happens or the contrast agent is injected intothe submucosa to obstruct the orifice of a pancreatic duct, draining ofpancreatic juice is interrupted, resulting in increasing possibility todevelop pancreatitis. As another method, there is a method in which aguidewire having a flexible distal end that is relatively easily bent isprotruded by about 2 to 3 mm from the distal end of the catheter toaccess the bile duct. Since the distal end of the guidewire is flexiblebut narrow, force is likely to concentrate on a single point andtherefore excessive stabbing may cause an edema or the guidewire to bethrust into the submucosa. Thus, in order to prevent pancreatitis, it isnecessary to decrease the risk of the edema or the puncturing of themucous membrane as much as possible.

In the conventional procedures, the distal end portion of the catheterwhere an opening of the lumen for passing a contrast agent is rounded asmuch as possible so that the distal end portion of the catheter does notcause the edema or the puncturing of the mucous membrane.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, a treatment deviceincludes a catheter having a lumen that is opened to a distal end of thecatheter, a wire passing through the lumen so that the wire is insertedinto or retracted from the lumen; and a piece disposed at a distal endof the wire and having a maximum width when the piece is protruded outfrom the distal end of the catheter is set larger than the diameter ofthe lumen, wherein the piece is formed of a deformable material having abroad curved surface shape that distributes concentration of pressureacting on tissues, and when the wire is pulled in toward the catheter,the piece being extended in the axial direction by the lumen and reducedin its outer diameter so as to be pulled into the lumen.

According to a second aspect of the invention, a treatment deviceincludes a catheter having a lumen that is opened to a distal end of thecatheter; a wire passing through the lumen so that the wire is insertedinto or retracted from the lumen; and a piece disposed at a distal endof the wire and formed of a deformable material, wherein the piece bodyhas a curved surface shape that distributes concentration of pressureacting on tissues, and when the piece is protruded out from the distalend of the catheter, a projected area of the piece as seen from thefront side in the axial direction of the catheter being set larger thanthe cross-sectional area in the axial direction of the lumen, while whenthe wire is pulled in toward the catheter to deform the piece body so asto be pulled into the lumen, the projected area of the piece body asseen from the front side in the axial direction of the catheter beingdecreased to be smaller than or equal to the cross-sectional area of thelumen.

According to a third aspect of the invention, a treatment deviceincludes a catheter having a lumen that is opened to a distal end of thecatheter; a wire passing through the lumen so that the wire is insertedinto or retracted from the lumen; and a piece disposed at a distal endof the wire and formed of a deformable material, wherein the piece bodyhas a curved surface shape that distributes concentration of pressureacting on tissues, and when the piece is protruded out from the distalend of the catheter, a width of the piece body in a first directionperpendicular to the axial line of the catheter being set larger thanthe diameter of the lumen and the width of the piece body in a seconddirection perpendicular to both the axial line and the first directionbeing set smaller than the diameter of the lumen, while when the wire ispulled in toward the catheter, the piece body being deformed in a mannerto alter the width in the first direction so as to be received into thelumen.

According to a fourth aspect of the invention, a treatment deviceincludes a catheter having a lumen that is opened to a distal end of thecatheter; a wire passing through the lumen so that the wire is insertedinto or retracted from the lumen; and a piece disposed at a distal endof the wire and formed of a deformable material, wherein the piece bodyhas a curved surface shape that distributes concentration of pressureacting on tissues, a maximum width of the piece body when the piece isprotruded out from the distal end of the catheter being set larger thanthe diameter of the lumen, the cross-sectional area at the maximum widthportion of the piece body in a direction perpendicular to the axial lineof the catheter being set smaller than the section area of the lumen ina direction perpendicular to the axial line of the lumen, and when thewire is pulled in toward the catheter, the maximum width portion beingdeformed so that the piece is received into the lumen.

According to a fifth aspect of the invention, a treatment deviceincludes a catheter having a guidewire lumen, a knife lumen, and aliquid supply lumen; a wire passing through the guidewire lumen so thatthe wire is inserted into or retracted from the guidewire lumen; a piecedisposed at a distal end of the wire with the maximum width when thepiece is protruded out from a distal opening of the guidewire lumen isset larger than the diameter of the guidewire lumen, the distal piecehaving a deformable piece body; and a conductive wire passing throughthe knife lumen, a portion of the conductive wire being exposed from theouter periphery on the distal end side of the catheter.

According to a sixth aspect of the invention, a treatment deviceincludes a catheter having a guidewire lumen and a liquid supply lumen,an opening of the guidewire lumen being disposed on a distal end surfaceof the catheter, and the distal end of the liquid supply lumen beingconnected to the guidewire lumen; a wire passing through the guidewirelumen so that the wire is inserted into or retracted from the guidewirelumen; and a piece disposed at a distal end of the wire with the maximumwidth when the piece is protruded out from a distal opening of theguidewire lumen is set larger than the diameter of the guidewire lumen,the distal piece is formed of a deformable material provided with a slittherein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing a configuration of a treatmentdevice;

FIG. 2 is a cross-sectional view taken along the line A-A in FIG. 1;

FIG. 3 is a view ken from the arrow B in FIG. 1;

FIG. 4 is a cross-sectional view taken along the line C-C in FIG. 1;

FIG. 5 is a view showing the case in which a distal piece is housed in alumen;

FIG. 6 is a view taken from the arrow D in FIG. 5;

FIG. 7 is a cross-sectional view taken along the line E-E in FIG. 5;

FIG. 8 is a view showing the case in which a distal piece is insertedinto a papilla;

FIG. 9 is a view showing the case in which a distal piece and a distalend portion of a sheath are inserted through a papilla into a bile duct;

FIG. 10 is a view showing the case in which a catheter is inserted intoa curved bile duct;

FIG. 11 is a view showing the case in which a catheter and a distalpiece are bent and advanced in accordance with the shape of a bile duct;

FIG. 12 is a view showing the case in which a distal piece is made toprotrude out from a catheter and is bent and advanced in accordance withthe shape of a bile duct;

FIG. 13 is a view showing the case in which a distal piece is made to beadvanced from a catheter in a manner similar to the case of FIG. 12;

FIG. 14 is a view showing another example of the shape of a distalpiece;

FIG. 15 is a view taken from the arrow F in FIG. 14;

FIG. 16 is a view taken from the arrow G in FIG. 14;

FIG. 17 is a view taken along the line H-H in FIG. 15;

FIG. 18 is a view showing the case in which a distal piece is housed ina lumen;

FIG. 19 is a view taken from the arrow J in FIG. 18;

FIG. 20 is a view taken along the line I-I in FIG. 18;

FIG. 21 is a cross-sectional view of a treatment device in which a slitis formed in a distal piece;

FIG. 22 is a cross-sectional view taken along the line K-K in FIG. 21;

FIG. 23 is a view taken from the arrow L in FIG. 21;

FIG. 24 is a cross-sectional view taken along the line M-M in FIG. 22;

FIG. 25 is a view showing the case in which a distal piece is housed ina lumen;

FIG. 26 is a view taken from the arrow N in FIG. 25;

FIG. 27 is a view taken along the line 0-0 in FIG. 25;

FIG. 28 is a sectional view of a treatment device with a hollow distalpiece;

FIG. 29 is a sectional view taken along the line P-P in FIG. 28;

FIG. 30 is a view taken from the arrow Q in FIG. 28;

FIG. 31 is a cross-sectional view taken along the line R-R in FIG. 28;

FIG. 32 is a view showing the case in which a distal piece is housed ina lumen;

FIG. 33 is a view taken from the arrow S in FIG. 32;

FIG. 34 is a view taken along the line T-T in FIG. 32;

FIG. 35 is a cross-sectional view of a multi-lumen treatment device;

FIG. 36 is a cross-sectional view of a papillotome as an example of atreatment device, in which an incision knife portion is provided using amulti-lumen sheath;

FIG. 37 is a cross-sectional view taken along the line U-U in FIG. 36;

FIG. 38 is a view showing the case in which a distal end of apapillotome is inserted into a papilla;

FIG. 39 shows an endoscopic image of an incised papilla

FIG. 40 is a cross-sectional view of a multi-lumen treatment device.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, exemplary embodiments of the present invention will bedescribed. Similar or identical components will be referenced by thesame reference numerals throughout the embodiments, and overlappingdescriptions will be omitted.

First Embodiment

As shown in FIG. 1, a treatment device 1 has a flexible insertionsection 3 extending in a longitudinal direction from an operationsection 2 with which an operator operates the treatment device 1.

The insertion section 3 has a catheter 4. A single lumen 5 is formed inthe catheter 4 so that a wire 6 can be freely advanced and retreatedthrough the lumen 5. The lumen 5 is a guidewire lumen so in addition tothe wire 6, a contrast agent can be injected through the lumen or otherguidewires may be inserted through the lumen. If the lumen 5 is used foronly the purpose of liquid supply, the lumen 5 only requires a smalldiameter of about 0.3 mm. To allow passage of guidewires or othertreatment tools, a larger lumen diameter is required. The guidewireshave various diameter specifications. For example, most typicalguidewires have an outer diameter of 0.035 inches (0.89 mm), and asuitable inner diameter of the lumen 5 for these guidewires is in therange of about 0.9 to 1.2 mm. Thinner guidewires have an outer diameterof 0.025 inches (0.64 mm) or 0.018 inches (0.46 mm), and an optimumlumen diameter for these guidewires is in the range of about 0.7 to 0.8mm or in the range of about 0.5 to 0.6 mm, respectively.

A distal opening of the lumen 5 is formed in a distal end surface 4A ofthe catheter 4. An outer peripheral portion of the distal end surface 4Aof the catheter 4 is cut in a tapered shape with reduced diameter towardthe distal end, so as to improve ability to insert the catheter 4 into aduct cavity. The catheter 4 is a tube made of polytetrafluoroethylene(PTFE) or polyethylene resin, for example.

The wire 6 is reduced in diameter toward the distal end, and a distalpiece 10 is fitted to an end portion 6A having the smallest diameter bymeans of adhesive or the like.

The wire 6 may be formed of a metallic wire (stainless steel, NiTi), aplastic solid rod, or a metallic wire covered with a plastic cover. Theuse of a plastic solid rod or of a metallic wire covered with a plasticcover enables a combined use of the wire 6 and a catheter that uses ahigh-frequency current, such as a papillotome. The diameter at theportion of the wire 6 inserted through the catheter 4 is smaller thanthe lumen diameter. For example, if the catheter is compatible with0.035 inch guidewire and the lumen diameter is 1 mm, the diameter at theportion of the wire 6 is set to about 0.8 mm or smaller.

The distal piece 10 is arranged such that a solid spherical piece body12 is integrally formed with a base portion 11 that covers the outerperiphery of the end portion 6A on the distal end side of the wire 6. Asshown in FIG. 2, the outer diameters of the base portion 11 and theportion of the wire 6 located closer to the operator side than the baseportion 11 are smaller than the diameter of the lumen 5. As shown inFIG. 1, in a state in which the piece body 12 is protruded from thedistal end, the maximum outer diameter of the piece body 12 is setlarger than the diameter of the lumen 5 and smaller than the outerdiameter of the catheter 4. For example, the maximum outer diameter isabout 1.2 mm if the lumen diameter is 1 mm. An axial length L1 of thepiece body 12 having a substantially spherical shape is equal to orsmaller than or equal to twice of the lumen diameter. Since the distalpiece 10 has a curved surface shape that distributes concentration ofpressure acting on tissues, a distal end portion of the insertionsection 3 becomes to assume a rounded shape. Here, the curved surfaceshape for distributing the concentration of pressure acting on tissuesrefers to a curved surface shape that has an area larger than that ofthe distal end of the conventional guidewire or of the distal end of theconventional catheter and has a large curvature (hereinafter such ashape will be referred to as a broad and large-curvature curved surfaceshape). The length L1 being equal to or smaller than or equal to twiceof the lumen diameter is suitable for rounding off the distal end of theinsertion section 3 without creating a sharp-edged shape.

As shown in FIG. 3, a projected area Sc1 of the piece body 12 as seenfrom the front side in the axial direction of the piece body 12 is setlarger than a cross-sectional area S11 of the lumen 5 perpendicular tothe axial line of the lumen 5. As shown in FIG. 4, a cross-sectionalarea Dc1 of the piece body 12 at a portion having a maximum width in adirection perpendicular to the axial line (hereinafter the portion willbe referred to as a maximum width portion) is set larger than thecross-sectional area S11 of the lumen 5. Alternatively, the piece body12 may have a bombshell shape.

The distal piece 10 is formed of a deformable material such as anelastic material. When it is desired to have the piece body 12 have adiameter much larger than the lumen diameter, suitable examples of theelastic material include rubber having a relatively large elasticity(for example, latex rubber, silicone rubber, and urethane rubber) andelastomeric plastic (for example, polyamide elastomer and urethaneelastomer). A contrast material such as bismuth oxide, barium sulfate ortungsten may be mixed with the elastic material, allowing X-rays to betaken. In addition, the outer surface of the distal piece 10 issubjected to a lubrication treatment (for example, hydrophilic lubricantcoating, water-repelling lubricant coating, teflon coating, and siliconeoil coating).

Since the distal piece 10 is formed of an elastic material, the distalpiece 10 can be deformed and housed in the catheter 4. When the wire 6is pulled in toward the catheter 4, the distal piece 10 collides againstthe distal end surface 4A of the catheter 4 so the distal piece 10 isdeformed in a manner to extend in the axial direction. Accordingly, theouter diameter of the piece body 12 is decreased to be smaller than orequal to the lumen diameter and is thus pulled into the lumen 5. As aresult, as shown in FIG. 5, the piece body 12 is crushingly reduced inits maximum outer diameter. Also, an axial length L2 becomes larger thanthe axial length L1. When the piece body 12 is pulled into the lumen 5,as shown in FIG. 6 which is taken from the arrow D in FIG. 5, aprojected area (Sc2 of the piece body 12 in the axial direction is alsodecreased. The projected area Sc2 of the piece body 12 when pulled intothe lumen 5 becomes smaller than or equal to the cross-sectional areaS11 of the lumen 5. As shown in FIG. 7, the cross-sectional area at themaximum diameter portion of the piece body 12 is decreased when pulledinto the lumen 5, and the cross-sectional area Dc2 of the piece body 12when pulled into the lumen 5 becomes smaller than or equal to thecross-sectional area S11 of the lumen 5. Here, since the distal piece 10is formed of an elastic material, the distal piece 10 can be restoredinto substantially the same shape as its original shape when the distalpiece 10 protrudes out from the distal end of the catheter 4 after beingpulled into the catheter 4.

As shown in FIG. 1, the operation section 2 has an operation body 21fixed to the proximal end of the catheter 4. The operation body 21 has ahole 22 that is formed therethrough. The hole 22 has a diameter equal toor larger than the diameter of the lumen 5. A liquid supply port 23 isconnected to the hole 22. The liquid supply port 23 protrudes from theside portion of the operation body 21 and a connector 23A is formed inthe end portion of the liquid supply port 23, A syringe (not shown)storing a contrast agent therein may be connected to the connector 23A.

The wire 6 passes through the hole 22 of the operation body 21. Thediameter of an end portion 22A of the hole 22 located closer to theproximal end than the liquid supply port 23 is enlarged. A sealingmember 25 is inserted in the end portion 22A and then a handle 26 isscrewed thereto. As the sealing member 25, a ring-shaped elastic membersuch as an O-ring can be used. The sealing member 25 can be compressedand deformed by rotating the handle 26 so that the inner diameterchanges between 0 and the lumen diameter or more. The diameter of thehandle 26 can be enlarged to a flange shape so an operator can easilygrip the handle 26, and a through-hole 27 is disposed concentric to thehole 22 of the operation main body 21. The wire 6 also passes throughthe through-hole 27. When the handle 26 is rotated in a state that thewire 6 is passed through the sealing member 25, the sealing member 25 issqueezed and thus the position of the wire 6 is fixed. At this time, aliquid-tight seal is formed in a space between the sealing member 25 andthe wire 6, preventing liquid supplied from the liquid supply port 23from leaking toward the operator side. In addition, a mark 28 isprovided on the wire 6. When the mark 28 is aligned at a proximalsurface 26A of the handle 26, on the distal end side, an inclinedsurface 12A of the piece body 12 located immediately before the proximalside from the maximum diameter portion is moved to a position where theinclined surface 12A almost collides against a distal opening 5A of thelumen 5 at the distal end surface 4A of the catheter 4.

Next, the procedure of ERCP using the treatment device 1 will bedescribed.

First, an endoscope is inserted through a natural orifice of a patient,a mouth, and is introduced into the duodenum. In this embodiment, aside-view type endoscope may be used having an observation window on aside portion thereof.

While taking images of the interior of the body using an observationdevice installed in the endoscope, the distal end of the endoscope isadvanced in the vicinity of a papilla of a treatment target. Thecatheter 4 of the treatment device 1 is inserted through a forceps plugof the endoscope disposed close to the operator side into an instrumentchannel. At this time, the distal piece 10 is in the state shown in FIG.1: i.e., the distal piece 10 is protruded out so as to almost collideagainst the distal end surface 4A of the catheter 4. Moreover, thehandle 26 is rotated to decrease the inner diameter of the sealingmember 25, fixing the position of the wire 6.

As shown in FIG. 8, the catheter 4 is protruded out toward a papilla DNby a forceps elevator 32 provided at the distal end of an endoscope 31.With the angle control of the endoscope 31, the control of the forcepselevator 32, and the advancing and retracting of the catheter 4, thedistal end of the catheter 4 is inserted into the papilla DN. At thistime, since the distal piece 10 has the broad, large-curvature curvedsurface shape, the force applied thereto at the time of the insertion isdistributed. Moreover, since the distal end of the treatment device 1 isgenerally smooth and rounded, the distal end does not damage or thrustinto mucous membranes. As shown in FIG. 9, the distal end of thecatheter 4 and the distal piece 10 are inserted through the papilla DNinto further inside of a bile duct BD in a smooth manner. Here, as shownin FIG. 10, even if the bile duct BD is greatly curved, since the piecebody 12 of the distal piece 10 makes contact with tissues on thespherical surface having the broad, large-curvature curved surfaceshape, the force applied from the treatment device 1 to the wall of thebile duct BD is not concentrated thereon but distributed over a broadarea. For this reason, a small load is applied to the wall of the bileduct BD. When the catheter 4 is pushed further into the bile duct BD, asshown in FIG. 11, the catheter 4 and the wire 6 are deformed, curved andinserted through the bile duct in a manner to assume the shape of thebile duct BD.

As shown in FIG. 12, the catheter 4 may not be inserted at all but onlythe wire 6 may be pushed into the bile duct BD. In this case, the handle26 is loosened to push in only the wire 6. Since the distal piece 10having a sufficiently large spherical shape is provided at the distalend of the wire 6, the wire 6 can be inserted into further inside of thepapilla DN in a smooth manner without damaging or thrusting into themucous membranes. Moreover, since a small-diameter portion 11 a isprovided to the base portion 11 disposed at the right rear side of thepiece body 12, the wire 6 can be more easily curved in a manner to adoptthe shape of the bile duct BD. As shown in FIG. 13, when the wire 6 isinserted beyond the papilla DN, the catheter 4 is inserted beyond thepapilla along the wire 6.

When the catheter 4 is inserted to a desired position, a contrast agentis injected from a syringe mounted on the liquid supply port 23. Thecontrast agent is introduced to the distal end along a path between thelumen 5 and the wire 6 and then injected into the bile duct BD through agap between the distal piece 10 and the catheter 4. With X-rayequipment, clear X-ray images of the bile duct BD can be taken.

Next, the wire 6 is pulled into the lumen 5 of the catheter 4. Here, ifthe catheter 4 is inserted together with the wire 6, the handle 26 isloosened to pull only the wire 6. Then, the distal piece 10 is deformedin a manner that the diameter becomes smaller than or equal to the lumendiameter and that the distal piece 10 is pulled into the lumen 5. Whenthe wire 6 is pulled further, the wire 6 passes through the catheter 4and is pulled out from the opening of the operation section 2 disposedcloser to the operator side in a state that the distal piece 10 isextended long and reduced in its diameter, projected area, andcross-sectional area. When the wire 6 is pulled out, other guidewirescan be inserted according to the purpose of use. Alternatively, bypulling out only the catheter 4 while leaving the wire 6 in the bileduct BD, other treatment tools may be inserted along the wire 6. Whennecessary treatments using other treatment tools are completed, the wire6 is pulled out of the bile duct BD.

In this embodiment, since the portion of the distal piece 10corresponding to the distal end portion of the insertion section 3 isformed in a smooth round shape, it is possible to insert the insertionsection 3 beyond the papilla DN in a smooth manner without damaging orthrusting into the mucous membranes. In the conventional procedure, evenwhen the distal end portion of the catheter is rounded, it was difficultto form the distal end of the insertion section in a completely smoothspherical surface shape, due to the presence of the edges of the distalopening of the guidewire insertion lumen. In the conventional art, whenusing a catheter having a narrow distal end, the distal end of theinsertion section becomes a narrow, sharp-edged shape. From this reasonand due to the presence of the edges of the lumen, the operation of theconventional tool and decision making by an operator upon using the toolrequired a great deal of caution. A method may be employed in which aguidewire having a flexible distal end that can be easily curved isprotruded by about 2 to 3 mm from the distal end of the catheter toaccess the bile duct. Though the guidewire is easily curved, since thedistal end of the guidewire of the conventional art is narrower than thelumen diameter of the catheter, if a large pressing force is appliedthereto, the pressure may be concentrated on a single point, therebydamaging or thrusting into the mucous membranes. Accordingly, theoperation required a great deal of caution. In this embodiment, byvirtue of the distal piece 10, the edges of the lumen 5 are not directlypressed on tissues, and the distal end portion of the insertion section3 is formed in a generally broad and rounded shape. Accordingly, theabove-described problems are solved or alleviated.

Since the distal piece 10 is configured to be elastically deformable,when the wire 6 is pulled from the operator side, the distal piece 10 isdeformed in a manner that the distal piece 10 is pulled into the lumen5. Therefore, the wire 6 and the distal piece 10 can be pulled out untilthe proximal side while the catheter 4 is indwelled. Accordingly, it ispossible to insert other guidewires according to necessity.

Since the distal piece 10 is subjected to a lubrication treatment, thedistal piece 10 is made more difficult to thrust into the mucousmembranes. Moreover, the distal piece 10 can easily slide its way to acurved duct cavity. In addition, since the friction between the distalpiece 10 and the inner wall of the lumen 5 is reduced, the distal piece10 can be easily deformed with a small force.

By mixing a contrast agent into the distal piece 10, it is possible toperform the insertion while imaging and observing the movement of thedistal piece 10 under X-rays.

The distal piece 10 may be integrally formed with the wire 6.

Second Embodiment

As shown in FIG. 17, in a treatment device 41, the distal piece attachedto the distal end of the wire 6 has a shape different from that of theabove-described embodiment.

The treatment device 41 is provided with a distal piece 42 having abroad, large-curvature curved surface shape that distributesconcentration of pressure acting on tissues, causing the distal endportion of the insertion section 3 to form a generally rounded shape.The distal piece 42 is provided with a piece body 43 configured toprotrude out from the distal end surface 4A of the catheter 4, and thepiece body 43 has a pair of flat side surfaces 44. The side surfaces 44are parallel to each other on both lateral portions of a solid sphericalbody. As shown in FIG. 15, a width d1 between the pair of flat sidesurfaces 44 is set smaller than the diameter of the lumen 5. A length d2of the piece body 43 in the vertical direction (first direction)perpendicular to both the horizontal direction (second direction)connecting the pair of side surfaces 44 and the axial direction is setsmaller than the outer diameter of the catheter 4. As shown in FIG. 16,a projected area Sc3 in the axial direction of the piece body 43 is setlarger than the cross-sectional area S11 of the lumen 5. In addition, asshown in FIG. 17, the cross-sectional area Dc3 of the piece body 43 atthe maximum width portion having a maximum width in the verticaldirection is set larger than the cross-sectional area S11 of the lumen5.

Similar to the case of the first embodiment, the distal piece 42 isformed of a deformable material such as an elastic material, and theouter surface of the distal piece 42 is coated. For this reason, asshown in FIG. 18, the distal piece 42 can be deformed and accommodatedin the lumen 5. As shown in FIG. 19, a projected area Sc4 in the axialdirection becomes substantially equal to the cross-sectional area S11 ofthe lumen 5. Also, as shown in FIG. 20, a cross-sectional area Dc4 atthe maximum width portion becomes substantially equal to thecross-sectional area S11 of the lumen 5.

The procedure of ERCP using the treatment device 41 is substantially thesame as that of the first embodiment. The insertion section 3 isinserted into the papilla DN in a smooth manner while preventing thedistal end portion from damaging or thrusting into mucous membranessince the distal piece 42 allows the distal end portion to form agenerally rounded shape. When an operator pulls the wire 6 in order topull out the wire 6, the piece body 43 is elastically deformed so thatthe piece body 43 is pulled into and passed through the lumen 5, wherebythe wire 6 is pulled out toward the operator side.

In this embodiment, the distal piece 42 is configured to have a broad,large-curvature curved surface shape that distributes concentration ofpressure acting on tissues, and the width d2 in the vertical directionof the piece body 43 is set larger than the lumen diameter, therebyalleviating or preventing damage or thrusting to mucous membranes. Withsuch a configuration, it is possible to achieve the same advantages asthe first embodiment. In addition, by configuring the width d1 in thehorizontal direction of the piece body 43 so as to be smaller than thelumen diameter, it is possible to decrease the extent of deformation inthe piece body 43 when pulled into the lumen 5. Therefore, it ispossible to decrease the amount of force required for the pulling, andthus the usability of the device is improved. In addition, it ispossible to decrease the load applied to the elastic material at thetime of deformation of the piece body 43, and thus the durability of thedevice is improved.

Third Embodiment

As shown in FIG. 21, in a treatment device 51, the distal piece attachedto the distal end of the wire 6 has a shape different from that of theabove-described embodiments.

A distal piece 52 is provided with a piece body 53 configured toprotrude out from the distal end surface 4A of the catheter 4. The piecebody 53 is formed of a deformable member such as an elastic memberhaving a broad, large-curvature curved surface shape that distributesconcentration of pressure acting on tissues, causing the distal endportion of the insertion section 3 to form a generally rounded shape.The piece body 53 has a pair of flat side surfaces 54. The side surfaces54 are parallel to each other on both lateral portions of a sphericalbody, and a slit 55 is formed across the side surfaces 54 so as topenetrate through the piece body 53.

As shown in FIGS. 21 and 22, a portion of the slit 55 extends to thebase portion 11 and forms a proximal end portion 11 b. As shown in FIG.23, a width d3 of the piece body 53 in the horizontal direction parallelto the slit 55 is set smaller than the diameter of the lumen 5. A widthd4 of the piece body 53 in the vertical direction perpendicular to boththe horizontal direction and the axial direction is set larger than thediameter of the lumen 5 and smaller than the outer diameter of thecatheter 4. A projected area Sc5 in the axial direction of the distalpiece 52 when disposed outside the lumen 5 is set larger than thecross-sectional area S11 of the lumen 5. As shown in FIG. 24, the totalarea of a cross-sectional areas Dc51 and Dc52 of the distal piece 52 ata portion having the maximum width d4 in the vertical direction is setsmaller than the cross-sectional area S11 of the lumen 5. In addition,to broaden the curved surface shape of the distal end of the piece body53, the shape of each of the cross-sectional areas Dc51 and Dc52 isconfigured such that the width d3 in the horizontal direction is setlarger than both respective widths d41 and d42 in the vertical directionof the cross-sectional areas Dc51 and Dc52 and that the cross-sectionalareas Dc51 and DcS2 are in a substantially semi-circular shape.

As shown in FIGS. 25 and 26, in a state in which the distal piece 52 ispulled into the lumen 5, the projected area Sc6 of the distal piece 52is set smaller than or equal to the cross-sectional area S11 of thelumen 5. FIG. 27 is a cross-sectional view taken at a positioncorresponding to FIG. 24: i.e., the position corresponding to themaximum width portion is shown. The width of the slit 55 is narrowed, sothat the solid core portions come closer to each other. The total areaof the cross-sectional areas Dc61 and Dc62 becomes smaller than or equalto the cross-sectional area S11 of the lumen 5.

The cross-sectional area at the proximal end portion 11 b disposed atthe right rear side of the piece body 53 becomes smallest in the baseportion 11.

The distal piece 52 is formed of a deformable material such as anelastic material. Since the piece body 53 is likely to be deformed bythe slit 55, the elastic material can be used may be a material having alower elasticity than rubber, such as polypropylene, polyethylene,polyurethane, polyamide, fluorine-contained resin, PEEK (polyether etherketone), or PET (polyethylene terephthalate). The same material as thefirst embodiment may be used. Another slit may be formed in the verticaldirection to cross the slit 55 so that there are slits in twodirections, or additional slits may be formed to cross each other inseveral directions.

The procedure of ERCP using the treatment device 51 is substantially thesame as that of the first embodiment. When an operator pulls out thewire 6, the piece body 53 is elastically deformed. The portion of thepiece body 53 making first contact with the distal end surface 4A of thecatheter 4 is deformed in a manner to decrease the width of the slit 55and decrease the exterior shape of the piece body 53, and in response tothis, the piece body 53 is pulled into the lumen 5.

In this embodiment, it is possible to achieve the same advantages as thefirst embodiment. Furthermore, since the slit 55 provides the sameadvantage as obtainable from the structure in which the distal end ofthe piece body 53 operates in a hinge manner, it becomes easy to changethe size of the piece body 53 in the diameter direction. In addition, itis possible to decrease the amount of force required for pulling in thepiece body 53, and thus the usability of the device is improved.Alternatively, it is possible to decrease the load applied to theelastic material at the time of deformation of the piece body 53, andthus the durability of the device is improved.

Since the cross-sectional area at the proximal end portion 11 b disposedat the Tight rear side of the piece body 53 is smallest in the baseportion 11, the piece body 53 is made easy to bend about the proximalend portion 11 b. For this reason, the wire can be more easily curved ina manner to adopt the shape of the bile duct BD.

Alternatively, a slit may be provided to the piece body 12 of the firstembodiment. In this case, the position or size of the slit is the sameas that of the slit 55 provided to the piece body 53.

Fourth Embodiment

As shown in FIG. 28, in a treatment device 61, the distal piece attachedto the distal end of the wire 6 has a shape different from that of theabove-described embodiments.

As shown in FIGS. 28 and 29, a distal piece 62 is provided with a piecebody 64 formed of an elastic material and having a broad,large-curvature curved surface shape that distributes concentration ofpressure acting on tissues. The piece body 64 has a hollow shape inwhich a void 65 is formed extending to a proximal end portion 63 that isfitted to the wire 6. For this reason, as shown in FIG. 30, a projectedarea Sc7 in the axial direction of the piece body 64 is greater than thecross-sectional area S11 of the lumen 5, however, as shown in FIG. 31, across-sectional area Dc7 at a maximum diameter portion of the piece body64 is smaller than the cross-sectional area S11 of the lumen 5. Othershapes or materials of the piece body 64 are the same as those of thefirst or third embodiment.

As shown in FIG. 32, when the piece body 64 is pulled into the lumen 5,the piece body 64 is squeezed to deform the void 65 in the distal piece62 in a long and thin manner. As shown in FIGS. 33 and 34, a projectedarea Sc8 in the axial direction and a cross-sectional area Dc8 at themaximum width portion become smaller than or equal to thecross-sectional area S11 of the lumen 5.

In this embodiment, since the void 65 is formed in the distal piece 62,the piece body 64 can be easily deformed and pulled into the lumen 5with a small force. In addition, the load applied to the distal piece 62can be decreased, and thus the durability of the device can be improved.Other advantages of this embodiment are the same as those of the firstembodiment.

The distal piece 42 of the second embodiment may be formed in a hollowshape.

Fifth Embodiment

As shown in FIG. 35, the insertion section 3 of a treatment device 71 isprovided with a multi-lumen type catheter 72.

The catheter 72 includes a first lumen, the guidewire lumen 5 forpassing the wire 6, and a second lumen, a liquid supply lumen 73disposed in parallel to the guidewire lumen 5. A distal opening of theliquid supply lumen 73 is disposed at the inclined portion in a taperedshape close to a distal end surface 72A of the catheter 72. A proximalend of the liquid supply lumen 73 is communicated with a liquid supplyport via a communication hole 75 formed in the operation main body 21.The liquid supply port 23 is not communicated with the guidewire lumen5.

The procedure of inserting the treatment device 71 into the bile duct BDthrough the papilla DN is the same as that of the above-describedembodiments. At the time of imaging, a contrast agent is supplied from asyringe to the liquid supply lumen 73 via the liquid supply port 23 andthe communication hole 75 and then supplied to the bile duct BD from thedistal opening of the liquid supply lumen 73.

In this embodiment, since the catheter 72 is configured as a multi-lumentype catheter, even when the distal piece 10 blocks the distal openingof the guidewire lumen 5, it is possible to allow the contrast agent tobe ejected from the distal end of the catheter 72. The distal piece 10provides the same advantages as in the case of the first embodiment.Alternatively, the distal piece may also be the one used in any one ofthe second to fourth embodiments.

Sixth Embodiment

As shown in FIG. 36, the treatment device of this embodiment is apapillotome 81 that can incise the papilla DN.

The papillotome 81 has the flexible insertion section 3 extending in alongitudinal direction from the operation section 2 with which anoperator operates the papillotome 81. The insertion section 3 has amulti-lumen type catheter 84. A conductive wire 86 which is used forincision is drawn out on a lateral portion on the distal end side of thecatheter 84.

As shown in FIG. 37, the catheter 84 has three lumens 91, 92, and 93that are substantially parallel to each other and extend in thelongitudinal direction.

A guidewire lumen 91 as the first lumen has the largest diameter amongthe three lumens and is opened to a distal end surface 84B of thecatheter 84. The wire 6 can be freely advanced and retracted through theguidewire lumen 91. The distal piece 52 is fitted to the wire 6. Thematerial and shape of the distal piece 52 and the size of the guidewirelumen 91 are the same as those of the third embodiment. In addition,guidewires other than the wire 6 may be inserted through the guidewirelumen 91.

A knife lumen 92 as the second lumen has the smallest diameter among thethree lumens, and the distal end thereof is sealed. Two holes 94 and 95are formed in the distal end of the knife lumen 92 in this order in thelongitudinal direction away from the distal end, and the holes areopened to a lateral portion of the catheter 84. The conductive wire 86is passed through the knife lumen 92. The conductive wire 86 is drawnout from the hole 94 formed in a lateral portion of the distal endsurface 84A of the catheter 84 to be exposed to the outside of thecatheter 84 and is inserted into the knife lumen 92 through the hole 95formed close to the distal end. The portion that is drawn out on theouter periphery of the catheter 84 to be exposed to the outside servesas a knife portion that is used for treatment (hereinafter the portionwill be referred to as an incision knife portion 86A). The distal end ofthe conductive wire 86 is fixed to the catheter 84 at a piece 96 that isburied in the knife lumen 92. When it is desired to bend the distal endportion 84A of the catheter 84 in a free curve shape, the distal endportion 84A may be provided with an ability to be bent in the directionfor shortening the linear distance between the two holes 94 and 15.

A liquid supply lumen 93 as the third lumen has the second largestdiameter among the three lumens, and the distal end thereof is opened.The liquid supply lumen 93 is used for supply of liquid such as acontrast agent.

The operation section 2 shown in FIG. 36 is provided with a firstbifurcated portion 100 that communicates a tube 102 to the guidewirelumen 91 in the catheter 84. The tube 102 is flexible and is connectedto an inserting section 103 at its end. The inserting section 103 has anopening so that the wire 6 can be inserted through the opening. A ring104 is formed on a lateral portion of the inserting section 103. Thering 104 has a substantially C-shape that is opened at the distal endside. When the ring 104 is fitted to the endoscope, the operationsection 2 can be fixed to the endoscope. A connecting portion 105 isintegrally formed with the lateral portion of the inserting section 103substantially opposite the disposition position of the ring 104. Aconcave portion 105A is formed in the distal end of the connectionportion 105.

The operation section 2 is provided with an operation main body 106 thatis fixed to an end portion 84C of the proximal end portion of thecatheter 84 extending over the first bifurcated portion 100. Theoperation main body 106 has a lock portion 107 on its distal end. Thelock portion 107 is detachably fitted to the concave portion 105A of theconnecting portion 105. The operation main body 106 is bifurcated at asecond bifurcated portion 108 from the lock portion 107 into a firstoperation unit 109 and a second operation unit 110. The first operationunit 109 is disposed substantially concentric to the catheter 84 and iscommunicated to the liquid supply lumen 93, and a syringe can bedetachably fitted to its end. The second operation unit 110 is disposedinclined with respect to the first operation unit 109, and a slider 112can freely advance and retract. A terminal 113 connectable to anexternal high-frequency power supply is installed in the slider 112 andis electrically connected to the conductive wire 86 that is fixed to theslider 112.

Next, the procedure using the papillotome 81 will be described.

While taking images of the interior of the body using an observationdevice installed in the endoscope, the distal end of the endoscope isadvanced in the vicinity of a papilla of a treatment target. Thepapillotome 81 is inserted through a forceps plug of the endoscope intoan instrument channel, and the distal end portion 84A of the catheter 84is protruded from the endoscope. As shown in FIG. 38, the papillotome 81is protruded out in the lateral direction by a forceps elevator 132provided at the distal end of an endoscope 131. The distal edge of thecatheter 84 is inserted through the papilla DN into the bile duct BD bythe pre-curved shape of the distal end portion 84A. The distal endportion 84A of the catheter 84 can be inserted in a smooth manner whilepreventing the distal piece 52 from thrusting into the mucous membrane.A contrast agent is injected into the liquid supply lumen 93 from thesyringe fitted to the first operation unit 109. The contrast agent isinjected into the bile duct BD through the liquid supply lumen 93.

When an operator hooks his or her finger on a slider 112 and a ring 110Aon the proximal end of the second operation unit 110 so as to retractthe slider 112, the conductive wire 86 is pulled. Since the distal endof the conductive wire 86 is fixed to the distal end portion 84A of thecatheter 84, the distal end portion 84A of the catheter 84 is curved.Depending on the requirements, only the wire 6 may be pushed furtherinto the bile duct BD so that the distal end portion 84A is curved afterthe catheter 84 is stabilized. Since the incision knife portion 86A ofthe conductive wire 86 exposed to the outside from the catheter 84 ishung in an arch-like shape, the forceps elevator 132 is operated tooscillate the catheter 84 while flowing a high-frequency current fromthe high-frequency power supply to the conductive wire 86 via theterminal 113 on the slider 112 of the second operation unit 110. By thehigh-frequency current supplied to the tissue of the papilla DN makingcontact with the incision knife portion 86A and the tensile pressure ofthe incision knife portion 86A, the papilla DN is incised as shown inFIG. 39. When the papilla DN is sufficiently incised, theelectrification of the high-frequency current is stopped. FIG. 39 showsan endoscopic image taken by the observation device disposed at thedistal end of the endoscope 131.

When the incision of the papilla DN is completed, the slider 112 of thesecond operation unit 110 is restored to its normal position. Then, thecatheter 84 is advanced into the bile duct BD through the papilla DN.

When the treatment is completed, the papillotome 81 is pulled out fromthe bile duct BD to retract the endoscope out of the body. When thetreatment is continued using other treatment tools, the catheter 84 isadvanced into the bile duct BD and the wire 6 is pulled out from theguidewire lumen 91. The distal piece 52 is pulled into the guidewirelumen 91 and drawn out of the inserting section 103 while beingelastically deformed. Then, another guidewire is inserted through theinserting section 103 and introduced into the bile duct BD. Thereafter,the papillotome 81 is pulled out of the body while the guidewire isindwelled. Another treatment tool is introduced into the bile duct alongthe guidewire in order to perform a necessary treatment. Alternatively,only the papillotome 81 may be pulled out while the wire 6 is indwelledso that another treatment tool is inserted along the wire 6 in order toperform the treatment. When the treatment is completed, the treatmenttool, the guidewire and the endoscope are retracted.

In this embodiment, since the incision of the papilla and fluoroscopycan be performed with a single treatment device, it is possible toobviate the necessity of changing to another device. Since theorientation of the distal end of the catheter 4 can be controlled by anoperator's handle operation, it is possible to insert the papillotome 81in a more reliable manner. The distal piece 52 provides the sameadvantages as in the case of the above-described embodiments.Alternatively, the distal piece may also be the one used in any one ofthe first, second and fourth embodiments.

Seventh Embodiment

As shown in FIG. 40, the insertion section 3 of a treatment device 111is provided with a multi-lumen type catheter 112.

The catheter 112 includes a first lumen which is the guidewire lumen 5for passing the wire 6, and a second lumen which is the liquid supplylumen 73 disposed in parallel to the guidewire lumen 5. The distal endof the guidewire lumen 5 is opened to a distal end surface 72A of thecatheter 72. The distal opening 73A of the liquid supply lumen 73 is notopened to the distal end surface 72A of the catheter 72 but opened tothe vicinity of the distal end surface 72A disposed closer to theproximal end than the distal opening of the guidewire lumen 5. Thedistal opening 73A is communicated to the outside via the guidewirelumen 5.

A slit 55 is formed in the distal piece 52 disposed at the distal end ofthe wire 6.

The procedure of inserting the treatment device 111 into the bile ductBD through the papilla DN is the same as that of the above-describedembodiments. At the time of imaging the bile duct BD, a contrast agentis injected from a syringe into the liquid supply port 23. The contrastagent is supplied to the liquid supply lumen 72 through thecommunication hole 75. The contrast agent is introduced into theguidewire lumen 5 from the distal opening 73A of the liquid supply lumen73. Since the distal opening 73A is disposed in the vicinity of thedistal end surface 72A of the catheter 72, the contrast agent isinjected into the bile duct BD through the gap between the guidewirelumen 5, the wire 6, and the distal piece 52. Even when the distal piece52 is in proximity to or in close contact with the distal opening of theguidewire lumen 5, the contrast agent is injected into the bile duct BDthrough the slit 55 formed in the distal piece 52 and extending to theproximal end portion 11.

In this embodiment, since the distal opening 73A of the liquid supplylumen 73 is not disposed at the distal end surface 72A of the catheter72, the multi-lumen type catheter 72 can have a smoother tapered portionat its distal end. By virtue of the slit 55 of the distal piece 52, itis possible to allow the contrast agent to be ejected from the distalend of the catheter 72 in a reliable manner.

Since the distal piece 52 only needs to have a shape that allows elasticdeformation and enables the liquid supply, the slit may be formed on theouter periphery of the distal piece 52. In addition, in the papillotome81, the distal opening 73A of the liquid supply lumen 73 may beconnected to the distal end portion of the guidewire lumen 5.

While preferred embodiments of the invention have been described andillustrated above, the invention is not limited thereto. Additions,omissions, substitutions, and other modifications can be made withoutdeparting from the scope of the invention. Accordingly, the invention isnot to be considered as being limited by the foregoing description, andis only limited by the scope of the appended claims.

1. A treatment device, comprising: a catheter having a lumen that isopened to a distal end of the catheter; a wire passing through the lumenso that the wire is inserted into or retracted from the lumen; and apiece disposed at a distal end of the wire and having a maximum widthwhen the piece is protruded out from the distal end of the catheter isset larger than the diameter of the lumen; wherein the piece body beingformed of a deformable material has a broad curved surface shape thatdistributes concentration of pressure acting on tissues, and when thewire is pulled in toward the catheter, the piece being extended in anaxial direction by the lumen and reduced in its outer diameter so as tobe pulled into the lumen.
 2. A treatment device, comprising: a catheterhaving a lumen that is opened to a distal end of the catheter; a wirepassing through the lumen so that the wire is inserted into or retractedfrom the lumen; and a piece disposed at a distal end of the wire formedof a deformable material, wherein the piece body has a curved surfaceshape that distributes concentration of pressure acting on tissues, andwhen the piece is protruded from a distal end of the catheter, aprojected area of the piece as seen from the front side in an axialdirection of the catheter being set larger than a cross-sectional areain an axial direction of the lumen, while when the wire is pulled intoward the catheter to deform the piece body so as to be pulled into thelumen, the projected area of the piece as seen from the front side inthe axial direction of the catheter being decreased to be smaller thanor equal to the cross-sectional area of the lumen.
 3. A treatmentdevice, comprising: a catheter having a lumen that is opened to a distalend of the catheter; a wire passing through the lumen so that the wireis inserted into or retracted from the lumen; and a piece disposed at adistal end of the wire and formed of a deformable material, wherein thepiece body has a curved surface shape that distributes concentration ofpressure acting on tissues, and when the piece is protruded out from adistal end of the catheter, a width of the piece body in a firstdirection perpendicular to an axial line of the catheter being setlarger than a diameter of the lumen and a width of the piece body in asecond direction perpendicular to both the axial line and the firstdirection being set smaller than the diameter of the lumen, while whenthe wire is pulled in toward the catheter, the piece body being deformedin a manner to decrease the width in the first direction so as to behoused in the lumen.
 4. A treatment device, comprising: a catheterhaving a lumen that is opened to a distal end of the catheter; a wirepassing through the lumen so that the wire is inserted into or retractedfrom the lumen; and a piece disposed at a distal end of the wire andformed of a deformable material, wherein the piece body has a curvedsurface shape that distributes concentration of pressure acting ontissues, a maximum width of the piece body when the piece is protrudedout from a distal end of the catheter being set larger than a diameterof the lumen, a cross-sectional area at the maximum width portion of thepiece body in a direction perpendicular to an axial line of the catheterbeing set smaller than a section area of the lumen in a directionperpendicular to the axial line of the lumen, and when the wire ispulled in toward the catheter, the maximum width portion being deformedso that the piece is housed in the lumen.
 5. The treatment deviceaccording to claim 1, wherein the deformable material of the piece bodyis more likely to deform than that of the catheter.
 6. The treatmentdevice according to claim 1, wherein a slit is formed in the piece body.7. The treatment device according to claim 6, wherein thecross-sectional area of the piece body at the slit formation portion ina direction perpendicular to the axial line of the piece body is setsmaller than the cross-sectional area of the lumen.
 8. The treatmentdevice according to claim 1, wherein the piece body has a hollow shape.9. The treatment device according to claim 2, wherein the deformablematerial of the piece body is more likely to deform than that of thecatheter.
 10. The treatment device according to claim 2, wherein a slitis formed in the piece body.
 11. The treatment device according to claim10, wherein the cross-sectional area of the piece body at the slitformation portion in a direction perpendicular to the axial line of thepiece body is set smaller than the cross-sectional area of the lumen.12. The treatment device according to claim 2, wherein the piece bodyhas a hollow shape.
 13. The treatment device according to claim 3,wherein the deformable material of the piece body is more likely todeform than that of the catheter.
 14. The treatment device according toclaim 3, wherein a slit is formed in the piece body.
 15. The treatmentdevice according to claim 14, wherein the cross-sectional area of thepiece body at the slit formation portion in a direction perpendicular tothe axial line of the piece body is set smaller than the cross-sectionalarea of the lumen.
 16. The treatment device according to claim 3,wherein the piece body has a hollow shape.
 17. The treatment deviceaccording to claim 4, wherein the deformable material of the piece bodyis more likely to deform than that of the catheter.
 18. The treatmentdevice according to claim 4, wherein a slit is formed in the piece body.19. The treatment device according to claim 18, wherein thecross-sectional area of the piece body at the slit formation portion ina direction perpendicular to the axial line of the piece body is setsmaller than the cross-sectional area of the lumen.
 20. The treatmentdevice according to claim 4, wherein the piece body has a hollow shape.21. A treatment device, comprising: a catheter having a guidewire lumen,a knife lumen, and a liquid supply lumen; a wire passing through theguidewire lumen so that the wire is inserted into or retracted from theguidewire lumen; a piece disposed at a distal end of the wire and with amaximum width when the piece is protruded out from a distal opening ofthe guidewire lumen is set larger than a diameter of the guidewirelumen, the distal piece formed of a deformable material; and aconductive wire passing through the knife lumen, a portion of theconductive wire being exposed from an outer periphery on a distal endside of the catheter.
 22. A treatment device, comprising: a catheterhaving a guidewire lumen and a liquid supply lumen, an opening of theguidewire lumen being disposed on a distal end surface of the catheter,and a distal end of the liquid supply lumen being connected to theguidewire lumen; a wire passing through the guidewire lumen so that thewire is inserted into or retracted from the guidewire lumen; and a piecedisposed at a distal end of the wire with a maximum width when the pieceis protruded out from a distal opening of the guidewire lumen is setlarger than a diameter of the guidewire lumen, the distal piece formedof a deformable material, and provided with a slit therein.